This invention pertains to methods for portioning foodstuff, and more particularly, for portioning a foodstuff in accordance with a predetermined shape by building a three-dimensional map of the foodstuff and then cutting the foodstuff in three dimensions.
The slaughterhouse industries have traditionally been labor intensive; however, as in other labor intensive segments of industry, attempts are being made to reduce manual labor, increase speed, and improve productivity. A particularly labor intensive task is the portioning of foodstuffs such as meats from beef, poultry or fish. An important goal in food portioning is consistency. For instance, restaurants want to serve portions that will not differ markedly from day to day in size, quality, fat content and/or other criteria. In order to meet minimum weight specifications, a food portion often has to exceed the acceptable minimum weight. This is because restaurants must take into account some of the variation that can exist between portions. In order to assure that all portions meet minimum specifications, it is usually necessary to use a target weight that is somewhat above the minimum. This may be a bonus to consumers but a problem for restaurateurs and others who may end up giving away a significant portion of their profit margin. By having consistent portions, restaurateurs can reduce the amount of excess that is built into the portions they serve, and consumers are more likely to receive the same quantity and quality of meat product.
Up until now, skilled workers usually bore the responsibility of cutting foodstuffs into constant weight or constant sized portions. These methods can and often do result in waste. Workers, in theory, can manually portion meat to about the same size of portions. However, workers, unlike machines, fatigue and the constant repetitive motion involved with butchering may lead to disabling injuries.
Therefore, the industry is aware of the need to increase the productivity of its work, without unduly burdening its workers. Several inventors have sought to devise ways to equally portion meats utilizing automated machinery to reduce manual labor. Therefore, methods and machines have been designed in an attempt to automatically cut food so that portions are of approximately equal weight.
One approach to introduce automation into the food portioning industry is to measure the cross sectional area of the foodstuff and assume that such area remains constant throughout the length of foodstuff. As the conveyer moves forward, a transverse cutting device is activated at equally spaced predetermined time intervals. This method achieves portions of equal thickness, but not necessarily equal weight, as the cross-sectional profile of each succeeding cut can be smaller or larger than the previous one. In order to achieve substantial equal weight portions, this method requires that a human operator trim the foodstuff so that it essentially conforms to a uniform cross-section along the longitudinal axis. Once this step is performed, the machine may proceed cutting at predetermined lengths. This method could lead to a large amount of waste, and inconsistent weight portions.
An improvement over the above method can take into account the cross-sectional area after each cut is made. From this measurement and the assumed density of the foodstuff, the thickness to achieve a desired weight can be calculated by integrating the cross sectional area over the length until the desired weight is reached. As the conveyor advances, its forward progress is monitored and the foodstuff is trimmed in a transverse manner at the point when the thickness corresponds to the calculated thickness. This process is repeated until the whole foodstuff, for example, a primal cut of beef, or a fish is portioned into individualized, nearly equal weight portions. However, this method does not account for indentations, significant contours, or tissue discontinuities appearing throughout the foodstuff, which can often affect the density. Further, these methods do not contemplate cutting in three dimensions, meaning that usually one dimension is always fixed, as happens with chicken breasts or a primal cut of beef. Chicken breasts may be portioned along the length and width, and a primal cut of beef, such as a loin, is cut lengthwise.
Other automated methods are aimed at producing food portions which trim fat to produce portions with acceptable quantities of lean meat in relation to fat. Again, with these methods, portioning is done in two dimensions. As with previous methods, the initial portioning is done by human operators to carve the initial starting block and only then, can the machine proceed. These methods can rely on a scanning apparatus to determine where the demarcations between fat, bone, or cartilage and meat lie. Scanning apparatus require light or X-ray radiation to detect the fat regions. After this determination is made, a machine can trim the fat from the lean tissue. Once the fat is removed, the resultant food portion is weighed and sorted. These methods are “after the fact,” since the weight or size of the individual food portions is not considered in determining the appropriate amount of portioning. The portions are simply sorted according to weight after the trimming operation is complete.
In a variant of a previous method, other methods of portioning involve scanning the foodstuff to determine the thickness of the foodstuff passing directly underneath the scanner. From the scan, a computer will be able to mark the cutting line at which to cut to achieve the predetermined weight or size. The cutting apparatus can move while the foodstuff also moves on the conveyor, or the conveyor may stop at a cutting station and allow the cutting apparatus to cut the portion. These methods are limited in that the only cut that can be made is in the transverse direction. Using this method, one is also limited to a foodstuff portion having the initial thickness.
Other methods are directed at ways of classifying meats to determine which cut will maximize profit, i.e., which cut of meat is selling at the highest price per pound at the current time. A computer may be used to calculate and determine a portioning strategy to maximize the amount of those portions which are selling at the highest price. These methods lack the capability to generate a three-dimensional map and are concerned only with making primal cuts of meat.
Other methods are directed at increasing the speed of the cutting devices, or perhaps cutting the foodstuff in two directions. However, these methods, as with the methods previously mentioned, assume that the foodstuff is fixed in one dimension, most commonly the thickness dimension. This may be unacceptable for a variety of reasons. Heretofore, attempts have not been made to portion foodstuffs automatically along a third dimension to arrive at the desired shape or weight. Portions of meat, particularly chicken breasts, have now increased in size so greatly that two-directional cuts simply are no longer suitable to trim the breasts down to desired portions.
Therefore, to date no method or apparatus has been devised that will build an accurate three-dimensional map of the foodstuff, including the indentations and contours, that is to be portioned, then compare the map to a predetermined form, and then through the use of a computer controlled system automatically cut the foodstuff in three dimensions so as to achieve the predetermined shape or weight. The method of the present invention seeks to accomplish this task. The present invention will further increase productivity in the methods for portioning foodstuffs, particularly those meats, such as beef, poultry or fish which have uneven surfaces, including indentations and contours, to achieve consistent portions.